Belt sander



prl 7, 1964 J. J.' KROGEN ETAL BELT SANDER Filed Sept. l5, 1961 .Y NV EN TOEl 5 .Eli/Q United States Patent O 3,127,712 BELT SANDER Julius J. Krogen, 809 N. .lanss St., Anaheim, Calif., and

Dean M. Logsdon, Anaheim, Calif.; said Logsdon assignor to said Krogen Filed Sept. 15, 1961, Ser. No. 138,321 1 Claim. (Cl. 51-148) This invention pertains to a new and improved belt sander for use in polishing and sanding the ends of cylindrical objects such as thevends of tubular pipe.

Many diiferent types of belt sanders have, of course, been manufactured and used in the past. These prior devices have been primarily intended to be used in order to create smooth, planar surfaces. Thus, for example, these prior sanders have frequently been used in order to sand hardwood oors or in order to put planar surfaces on various diiierent articles of manufacture. Because of the fact that these prior Sanders have been primarily intended to provide planar surfaces as a general rule they cannot be used as satisfactorily in creating a smooth surface upon a periphery of a cylindrical object such as, for example, a piece of copper tubing.

A broad object of the present invention is to provide a new and improved belt sander. A more specic object of this invention is to provide belt Sanders which can be satisfactorily used for polishing cylindrical and other similar objects as suggested by the preceding discussion so as to avoid placing upon such objects planar surfaces. A still further object of the present invention is to provide belt Sanders of this category which may be easily and inexpensively constructed and which are very effective for the purposes intended.

These and various other objects of this invention, as well as many specific advantages of it, will be more fully apparent from a detailed consideration of the remainder of this specication including the appended claim and the accompanying drawing in which there is shown a perspective View of a belt sander of this invention.

The accompanying drawing is primarily intended so as to clearly illustrate a presently preferred embodiment or form of a belt sander of this invention. From a careful consideration of this drawing and the remainder of this specification those skilled in the art in machine design will be able to realize that a number of different changes of a routine engineering character such as changes in bearing structure or the like may be made in the particular sander shown and described hereinafter without departing from the various features embodied within this sander as defined inthe appended claim.

As an aid to understanding this invention it can be stated in essentially summary form that it concerns belt Sanders, each of which is formed so as to include two rotatable drums attached to opposite extremities of a support and an idler drum which is rotatably mounted on arm means which in turn are pivotally mounted on this support between the initial drums. In a sander of this invention a sanding belt passes around all of these drums so as to extend in a generally triangular path, and spring means are provided in order to resiliently bias outwardly from the support the idler drum by pivoting the arm means supporting this idler drum so as to tend to increase the angle between these arm means and this support. Further, with the present invention an adjustable ledge is preferably pivotally mounted between the idler drum and one of the initially mentioned drums so as to be capable of being adjusted to a position approximately transverse to the path of the sanding belt between these two latter drums as the sander is utilized. Means are also attached to one of the initially mentioned drums for the purpose of rotating a sanding belt.

The actual nature of this invention will be more fully apparent from a detailed consideration of the accompanying drawing. Here there is shown a complete belt sander 10 of the present invention which includes a base 12 which supports a vertically extending support 14 of a channel-like shape. This support 14 has side walls 16. Small projections 18 in the nature of continuations of the side walls '16 are provided on the support 14 adjacent to the extremity of it. These projections 18 carry shafts 2t) upon which there are rotatably mounted cylindrical drums 22 and 24 having parallel axes.

Bolts 26 are attached to the side walls 16 adjacent to the uppermost of the two drums, drum 22, for the purpose of rotatably mounting extremities of arms 28 upon the support 14 so that these arms 28 are capable of being pivoted about a common axis which is parallel to the axes of rotation of the drums 22 and 24. The arms 28 are preferably connected by means of a web 30 which carries a small bracket 32 which in turn holds an eye boit 34. This eye bolt 34 is secured to a spring 35 which extends from the bolt 34 to a small lug 36 mounted upon the support 14 adjacent to the drum 22. The arms 28 hold a shaft 38 which in turn rotatably supports an idler drum 40 in such a manner that this drum 40 is capable of being rotated about an axis which is parallel to the axes of the drums 22 and 24 and the pivotal axes of the arms 2S.

In the sander 10 the drums 22, 24 and 40 are used in order to support a conventional, continuous sanding belt 42. When the belt 42 is installed as shown in the drawing it extends in a generally triangular path and is engaged by the idler drum 411 so that the angle defined by the arms 28 and the support 14 generally between the idler drum 40 and the drum 24 is an acute angle and so that other angle between the arms 28 and the support 14 generally between the idler drum 4@ and the drum 22 is an obtuse angle. With this construction the tension of the spring 35 will tend to urge the idler drum 40 against the sanding belt 42 so as to increase the height of the triangle deiined by the sanding belt 42, assuming that the portion of this sanding belt 42 extending between the drums 22 and 24 is the base of the triangle.

The sander 1t) also preferably includes a support ledge 44 which has side arms 46 having ends connected by means of a bar 47. The extremities of these side arms 46 remote from the bar 47 carry aligned cross-arms 48. Adjacent to the bar 47 these side arms 46 are attached to lugs 50 extending from the side walls 16 by means of bolts 52 so that the entire ledge 44 is capable of being pivoted about an axis which is also parallel to the axes of the drums 22 and 24. 1t will be noted that in the position shown the side arms 46 and the cross arms 48 of the ledge 44 extend generally around the sanding belt 42, and that at all times the cross arms 48 and that portions of the side arms 46 are located on the side of this sanding belt 42 remote from a support 14. The cross arms 48 are preferably spaced from one another a short distance so as to facilitate changing the belt 42.

In order to adjust the position of the ledge 44 with respect to the support 14 it is preferred to attach to one of the side arms 46 an arcuate, slotted holder 54 which extends in a circular path about the axes of the bolts 52. This holder 54 is adapted to be used with another bolt 56 in an established manner in order to secure the ledge 44 to the support 14 in a position in which it may be most conveniently used. Normally this ledge 44 is located so that the side arms 46 are generally in a plane transverse to the path of the sanding belt 42 between the drums 46 and 24.

In the sander 10 the sanding belt 42 is turned by means of a small electric motor 58 which is rotatably mounted upon a support 14 by means of a conventional shaft type motor mount 60. This motor is preferably connected to the drum 24 by means of a conventional V-belt and pulley drive 62.

From a consideration of the construction of the sander 1@ those skilled in the art will see that this sander 10 is comparatively inexpensive to manufacture and construct.

They will also realize that by virtue of the type of construction embodied Within this sander 1t! that the idler drum 49 does not primarily act so as to take up slack in the sanding belt 42, but acts in a manner so as to change position as when a pipe is applied to the sanding belt 42 above the ledge 44. Thus, during the use of the sander 1t) this idler drum 40 will be pulled generally toward the support 14 and as this occurs the sanding belt 42 is deformed so as to follow a curved path avoiding the creation of a planar surface upon a pipe or similar article. Because of this it is very simple to polish or sand the ends of cylindrical objects such as cylindrical, rigid copper tubing with the sander 10 so as to prepare such ends for insertion in appropriate fittings or the like. They will also realize that the adjustable character of the ledge 44 facilitates the utilization of the entire sander 10 in desired manners, particularly when different sized objects are to be sanded with this sander 1t).

Because of the nature of this invention it is to be considered as being limited solely by the appended claim forming a part of this disclosure.

We claim:

A belt sander which includes:

an upwardly extending elongated support having a top and a bottom;

separate drum means rotatably mounted on said support apart from each other and adjacent the top and bottom of said support, and defining a minimum distance therearound;

arm means pivotally mounted on said support so as to extend therefrom on one side of said support intermediate said separate drum means;

further drum means rotatably mounted on the extremity of said arm means remote from said support;

`a sanding belt of substantially greater length than said minimum distance extending around said separate drum means and said further drum means so that said arm means extends at nearly a right angle with respect to said support and so that said sanding belt extends in a generally triangular path;

spring means operatively secured to said arm means and said support for moving said arm means so as to move said further drum means against said belt means in an upwardly pivoted direction, said spring means permitting substantial deilection of said arm means and said belt when a Weak force is applied to said sanding belt;

means for rotating one of said separate drum means;

and

an adjustable ledge means pivotally mounted on said one side of said support, said adjustable ledge means extending around said belt between said separate drum means adjacent the bottom of said support and said vfurther drum means.

Wysong Feb. 13, 1906 Velmure July 25, 19-16 

